brainpopfandomcom-20200223-history
Mineral Identification/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby Moby shows a gold-colored rock to Tim. MOBY: Beep. TIM: That's not a gold nugget. Tim reads from a typed letter. TIM: Dear Tim and Moby, how can you tell one mineral from another? From, Rachel. Minerals have physical properties that let you tell them apart. An image shows Moby standing with a group of gray robots. TIM: There he is. I can pick Moby out of a crowd because he has certain physical traits that make him different from everybody else. For one thing; he's orange, and he's got that lost look on his face. An image shows a drawer full of crystals of the same color. TIM: Bring me a piece of quartz, Moby. Moby looks at the rocks under a magnifying glass. MOBY: Beep. TIM: Well, Moby; color is usually the first indication of what type of mineral you're dealing with. Images show quartz and calcite, clear crystals which look similar. TIM: Quartz crystals are milky white like these, but they look a lot like calcite, and some of that is in there too. Moby scratches his head. TIM: Moby needs to look at some other mineral properties. Moby scratches the rock on one of Tim's fingers. TIM: Ow! Hardness measures how easily a mineral can be scratched. Images show a finger scratching black graphite and a diamond scratching another diamond. TIM: You can scratch graphite with your fingernail, but it's extremely difficult to scratch a diamond. The mystery mineral scratched my fingernail alright, but my fingernail only registers in at 2.5 on the Mohs scale. The Mohs scale is a table that ranks the hardness of minerals. An image shows a Mohs scale measuring the hardness of Tim's finger. TIM: Calcite measures three and quartz is seven, so let's see what this steel file, which is a 6.5, does. An image shows two minerals and a steel file being measured by the Mohs scale. An animation shows Moby rubbing the mystery mineral on the steel file. It scratches the steel. TIM: Quartz scratches steel; calcite doesn't. This is looking like a piece of quartz so far. Let's check out its luster. An animation shows two shiny yellow rocks. TIM: Luster tells you how light reflects off of a mineral's surface. Minerals like Pyrite and Gold have a metallic luster, they're really shiny. Tim holds up the mystery mineral for Moby to look at. TIM: Our mineral is kind of pearly looking. Moby rubs the mystery mineral against a dark surface. It leaves a small streak. TIM: Streak is the mineral's color when it's powdered. Lots of minerals can be easily identified using the streak test. Hmm, it's pretty hard to see much there. An image shows a flat surface. TIM: Minerals that break along a smooth flat surface have cleavage. An image shows two minerals broken into jagged pieces. TIM: Minerals that break like ours did, with rough jagged edges, have fracture. Tim and Moby are in a lab, wearing protective glasses and aprons, and there is a flask of blue liquid on the table in front of them. TIM: Quartz is a mineral with fracture so I'm about ninety-nine percent sure that that's what we're dealing with. But there are always a few more tests to perform. Moby drops the mystery mineral into the liquid. Nothing happens to the mystery mineral. TIM:That settles it. Calcite would fizz when hydrochloric acid touched it. MOBY: Beep. TIM: Yeah, I like identifying minerals too. MOBY: Beep. TIM: So start a rock collection. Tim is reading a book. Moby carries a large rock over to him and drops it on Tim's foot. The rock breaks into pieces. TIM: Ow! Maybe you shouldn't be keeping these in the living room. Category:BrainPOP Transcripts